A simple combined-objective optimization method for coil configuration of air-core multi-coil magnet systems

Abstract

Due to the high current density of high temperature superconducting magnet, it is possible for accelerator magnets to generate sufficiently strong magnetic field without using any iron core. A new optimization method is proposed for this kind of air-core system. This method combine Biot–Savart law and gradient descent method to determine the coil position, geometry and applied current at once, to obtain high accuracy magnetic field and small superconductor usage in the same time. The balance between high field accuracy and low superconductor usage can be adjusted by optimizing the weighting parameter properly. An example of using this method on a cyclotron is given, to show that the optimization can be performed under complicated spatial and current limitation. This optimization method is fast, and can be performed easily using python package without using any high level optimization or calculation technique. With its simplicity and speed, this optimization can be used for various air-core magnet design in the future.